The present invention relates to a motor vehicle functional front end.
It is known that a motor vehicle functional front end is a structure found in front of the engine block and which has the function of supporting various items at the front of the vehicle, and mainly the engine block radiator.
A functional front end such as this has the benefit that it can be pre-equipped away from the vehicle assembly line and installed on the vehicle in a single operation.
Around the radiator, which is the main item in the functional front end, there are various items such as a bonnet catch or hinges, lighting units, various reservoirs or electronic units or computers.
Conventionally, the structure of the functional front end is determined by the presence of the radiator and the reinforcements which are obtained by overmoulding metal inserts or by a change in material. These reinforcements transfer the stresses which are due to the presence of the radiator to the functional front end attachment points.
In other words, the functional front end of the motor vehicle may be considered as being a multiple support which organizes the arrangement of the various parts of the vehicle around the radiator.
On vehicles which do not have a functional front end, the various items are fixed in turn to the chassis of the vehicle, on the vehicle assembly line.
In one particular embodiment of the invention, the functional front end comprises a means for linking the radiator to the upper crossmember, but this linking means provides only relative positioning of the radiator on the functional front end, without supporting its weight.
In a preferred alternative form of this embodiment, the linking means is meltable and demountable.
It is therefore embedded in motor manufacturer custom that it is the presence of the radiator and the concern to support this radiator using a structure initially separate from the vehicle which justify the presence of a functional front end which, as a corollary, fulfills the additional function of supporting other items arranged around the radiator.
The present invention goes against this preconceived idea whereby it is necessary to have some way of supporting the radiator in order to provide a functional front end on a vehicle.
The subject of the present invention is a motor vehicle functional front end comprising at least one upper crossmember capable of supporting the hinges or the catch for the vehicle bonnet, a support piece at each end of the crossmember, each support piece being capable of taking at least one lighting unit of the vehicle, a lower crossmember extending from one support piece to the other and belonging to the vehicle energy-absorption system, and a cavity located between the two crossmembers and the two support pieces and leaving space for any radiator there may be, supported by means external to the functional front end.
The functional front end according to the invention can be used with an engine which supports its own radiator, the functional front end being arranged around the radiator, without supporting it, so that it fulfills only the so-called additional functions of conventional functional front ends, which consist in supporting various items such as, in particular, the indicators, the fog lights, the headlight washers, the lateral repeaters, the horn, the bonnet stop, the bonnet seal, the active cruise control, the apron, the resonator, the washer fluid bottle, the electric case for switches and fuses, the LPG expander, the fuel filter, the computer, the convergent, the front fairing, the air intake and the alarm.
In one particular embodiment of the invention, the functional front end comprises a means of fixing the radiator to the upper crossmember, but this fixing means provides only relative positioning of the radiator on the functional front end, without taking its weight.
In a preferred alternative form of this embodiment, the fixing means is meltable and demountable.
In a preferred embodiment, the upper crossmember is a hybrid crossmember consisting of a metal alloy section piece reinforced with plastic ribs, and the support pieces are made of polypropylene strengthened with 30% long glass fibres (of the order of 12 mm long). The lower crossmember is chosen according to the vehicle impact resistance specification. This crossmember will preferably incorporate energy absorbers of the DANNER unit type.
The support pieces are advantageously screwed to the upper crossmember.
In one particular embodiment of the invention, the support pieces which are mounted at the ends of the crossmember comprise means of fixing to the longerons of the vehicle.
Thus, the support pieces form struts which stiffen the upper crossmember by virtue of the fact that they are secured to the longerons, and increase the overall inertia of the functional front end.
With a view to making the invention easier to understand, one embodiment thereof, given by way of an example which does not restrict the scope of the invention, will now be described with reference to the single appended figure which depicts the front of a motor vehicle.